1. Field of the Invention
The present invention relates to an automotive dynamoelectric machine that is mounted to a passenger car, or a truck, etc.
2. Description of the Related Art
In conventional automotive alternators, bearing accommodating portions are configured as separate members from a frame and are mounted to mount surfaces of the frame in a closely-fitted state. Rolling bearings are accommodated in the bearing accommodating portions, and a rotor that generates field magnetic flux is rotatably held by the frame by supporting a rotating shaft thereof in the rolling bearings. Slip rings are mounted to a portion of the rotating shaft that projects through the bearing accommodating portions. A brush apparatus includes: a brush holder that accommodates brushes; and a slip ring cover that covers an outer circumference of the slip rings. Airtightness of a space around the slip rings is maintained by covering the space in question in a tube body that is constituted by the brush holder and the slip ring cover (see Patent Literature 1, for example).
Patent Literature 1: Japanese Patent Laid-Open No. 2002-345198 (Gazette)
In conventional automotive alternators, because the rolling bearings, the slip rings, and the brushes, etc., are disposed in close proximity, service temperatures of each of these parts have been increasing in recent years with increases in automotive alternator output, and effects thereof on the service life of the rolling bearings and the brushes, etc., have become a problem.